We've had great success with the "Let's Talk Nitrous" thread, so I thought we'd start a couple of new ones that diverge from your general mod discussions.

Let's Talk Fuel Delivery:
======================
High-boost forced induction, increased horsepower, or nitrous oxide demands more fuel than stock systems can deliver efficiently. So let's look at what the products are out there, hear from those that have taken the plunge, and perhaps even come up with the best system(s) for our modded G's.

Items in this discussion will include:
* High Capacity Replacement or inline fuel pumps
* Fuel Rails
* Fuel Pressure Regulators
* Fuel Injectors
* Other tips and tricks

Please make sure to be concise in your discussion, descriptions and include pixes & links where possible.

======================



'03.5 Sedan 5a: BS/G, Prem, Aero/Body, Sport, Nav
Click for MODS - www.teamtransport.org/forums

 

So kicking off the discussion, here are some aftermarket fuel pumps that are "inline", meaning that you use them in conjuction with your existing fuel pump (which is in your gas tank). I believe that stock fuel pumps put through about 190lph


Walbro 255lph High Flow fuel pump for G35/350z. It is rated to provide add'l fuel needs up to 450hp. Cost at i-m-racing is $125.


Zex inline booster fuel pump ~$191. Universal and handles needs up to 650hp .

there are also replacement fuel pumps avail from sources, such as Power Enterprises:


This is a "trochoid" 255lph for around $288 (PE catalog price)

Direct replacement fuel pumps will not have a whine that is associated with inline pumps. therefore solutions like the PE will be quieter. However, correct me if i am wrong, but you can switch off the inline fuel pumps when not racing or taxing the engine, as your oem pump will meet those needs. Not sure if you need to find a different inline pump for that, but I remember having an electric fuel pump switch avail to me on my old galaxie that I did this on. I'd flick a switch to activate the e-pump.



'03.5 Sedan 5a: BS/G, Prem, Aero/Body, Sport, Nav
Click for MODS - www.teamtransport.org/forums

 

Im rebuilding my motor with rods and pistons and Im wondering what it takes to put in larger injectors ? I have a Vortech and will the R4 program be able to scale back a larger injector ? So it doesnt run rich at idle and cruise

Couldnt afford it when young...gonna play when Im old

 

Doesn't take much to put in new injectors. For our G's there are 380cc (part # TH380NZ - light blue) and 510cc (part # TH510NZ - brown) injectors avail from PE,with collars included. They run about $180 each.



Does anyone have the steps to accomplish a change out? This would definitely require some ECU work by TS.


'03.5 Sedan 5a: BS/G, Prem, Aero/Body, Sport, Nav
Click for MODS - www.teamtransport.org/forums

 

The Pe injectors are expensive !!!! I have a thread going at my350z asking if I can scale them back with my R4 program

Couldnt afford it when young...gonna play when Im old

 

Booger

You will be able to scale them back ... because they work just like the stock injectors do. The only problem with those is that they are more expensive. You can get them for about $144 each from a few vendors out there. I am selling my 380cc's btw, as I need to go with something far bigger to safely support up to 700-800 crank hp (so that I can safely be in the 600 range when the car is up and running).

 

Now to the main discussion:

1. Fuel pump: Do NOT get the zex or any other inlie pump. Get an in-tank replacement, like PE's 255 L/hr or Walbro's 255 L/hr pump that drop into the tank (the latter should cost about $120 or so).

2. Fuel pressure regulator: You will want to get a rising rate fuel pressure regulator (1:1 rate - this means that or every psi increase in boost, fuel pressure will increase by 1 psi...... this wll result in an unchanged differential fuel pressure). SAARD makes a very good RRFPR, as does aeromotive. These are adjustable regulators, that will allow you to set the baseline fuel pressure. There is a Cartech regulator that is supposed to be very good in quality, and is adjustable not only for baseline fuel pressure but also the fuel pressure rising RATE itself, as well as the rising ONSET. IMO, the less you have to adjust the better.

3. Fuel rails: AEM has been rumoured to be coming out with them soon. For now., if you MUS T get new fuel rails, AAM (Altered Atmosphere) $800 kit is your only option. Not sure if it is worth it though. the only part about the stock fuel rails that bothers me is that little skinny crossover to the d-side rail... which some say is not enough to provide for a equal fuel distriution. I don't think that is necessarily the case, as the fuel doesn't flow so fast as to make that an issue. Gotta ask Clint about it....

4. Fuel injectors: there are NO injectors out there aside form the PE and the Bosch injectors (used by the APS kit) that can just fit into the fuel rail without any othe rfunny adapters. Also, there are NO injectors out there AT ALL, that will just plug into the stock harness, except for PE's.

G

 

Gurgen:

what about the PE SIC to control the injectors from inside the car? I can't read kanji, so i was hoping your mechs could enlighten us.




P.S. I thought the walbro was an inline?

'03.5 Sedan 5a: BS/G, Prem, Aero/Body, Sport, Nav
Click for MODS - www.teamtransport.org/forums

 

hey

I think that's a unit that would control additional/secondary injectors. We don't need to concern ourselves with that, as we will not run secondary injectors (that's a REALLY poor wat of doing it imo).

Walbro makes many different ones. In fact, that zex one loooks like an in-line walbro.

G

 

Good info. Can you explain why an in-tank replacement is preferrable to an inline pump?

 

So that you do not have to cut any fuel lines.... something you definitely want to avoid, both for reasons of safety and aesthetics.

 

Ah, makes perfect sense. Seems obvious now :P

 

Also, I would hesitate in adding a 2nd pump without a fuel pressure guage. If the 2nd pump quits working you will not know most likely until the rods have broke... I have read a few instances where Vortech owners have ran into this, although I don't think anyone has blown an engine from it. If you have one pump and it quits working your car won't run.

I was told that the stock ECU is not capable of firing any injector larger then the 380cc PEs. I was told that something like the Greddy something or other (don't remember what the name is) is necesarry to hook between the ECU and the injectors. I have no idea if this is true or not. I two will be selling my PE 380cc injectors in order to get the bigger PEs or something else.

Kevin
www.KPtechnologies.net
AIM: KPiersonTec
04 DG Coupe / VDC Memory
OEM Remote Window up mod
Procharged / Crawford / TS

 

Gurgen;
"there are NO injectors out there AT ALL, that will just plug into the stock harness, "

I need to get into the stock harness to wire in my Venom kit, but I can't find it!
Do I have to remove the plenum (complete chamber, top and bottom) to reach the harness? or am I blind?
Any help will be appreciated.
Terry

 

Terry..

I said "there are NO injectors out there AT ALL, that will just plug into the stock harness, expect for PE's injectors" PE's plug right in, thats the beauty of it..... aside from the fact that they have multiple nozzles pointed in two directions, firing equal amounts of fuel right onto the back of each of the two intake valves. They are of VERY high quality.

As far as the ecu not being able to fire anything over 380cc is not entirely true, from what I know (I may be wrong ont his, as I haven't done much research). You can lower the baseline fuel pressure with an adjustable fuel pressure regulator, which will allow for the closed loop system (which can fire an injector for a minimum of 2.5ms) to apply little enough fuel for the ~1% throttle that is used at idle to achieve the 14.7 idling afr. Otherwise the car will idle richer than 14.7.

I will personally not be running a stock ecu with or without e-manage, I will be looking to do somethign more reliable as the hp levels simply demand it. Let's wait and see....